Multinuclear transition metal catalysts for preparation of multimodal polymer compositions

ABSTRACT

Novel compounds are provided that are useful as catalysts, particularly in the polymerization of addition polymerizable monomers such as olefinic or vinyl monomers. The compounds are multinuclear complexes of transition metals coordinated to at least one unsaturated nitrogenous ligand. Catalyst systems containing the novel compounds in combination with a catalyst activator are provided as well, as are methods of using the novel compounds in the preparation of polyolefins.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional of U.S. patent application Ser.No. 09/685,328, filed Oct. 5, 2000, which claims priority to U.S.Provisional Patent Application Serial No. 60/158,331, filed Oct. 6,1999.

TECHNICAL FIELD

[0002] This invention relates generally to the field of catalysis, andmore particularly relates to multinuclear complexes of transition metalsand unsaturated nitrogenous ligands that are useful, inter alia, aspolymerization catalysts. The invention additionally relates to methodsfor using the novel complexes as catalysts, particularly in thepreparation of multimodal polymer products such as multimodal polyolefincompositions.

BACKGROUND

[0003] Many processes and catalysts are known for the preparation ofhomopolymeric or copolymeric olefins and other polymers. Ziegler-Nattacatalyst compositions, developed in the 1950s, were found to beparticularly useful in the preparation of polyolefins. These catalystcompositions comprise transition metal compounds such as titaniumtetrachloride and an alkylaluminum (e.g., triethylaluminum) cocatalyst.The systems were found to be advantageous because of their highactivity, and were largely consumed during polymerization.

[0004] Subsequent catalyst systems have been designed to provide morecontrol over polymer structure and properties than could be achievedwith Ziegler-Natta catalysts. These later catalysts have well-definedactive sites and can be rationally designed to produce a specificpolymer product, i.e., having predetermined structure and properties.Such catalysts include, for example, metal complexes known as“metallocenes.” The term “metallocene” was initially coined in the early1950s to refer to dicyclopentadienyliron, or “ferrocene,” a structure inwhich an iron atom is contained between and associated with two parallelcyclopentadienyl groups. The term is now used to refer generally toorganometallic complexes in which a metal atom (not necessarily iron) iscoordinated to at least one cyclopentadienyl ring ligand. A. D. Horton,“Metallocene Catalysis: Polymers by Design,” Trends Polym. Sci.2(5):158-166 (1994), provides an overview of metallocene catalysts andtheir advantages, and focuses on now-conventional complexes of Group IVtransition metal complexes and cyclopentadienyl ligands (Cp₂MX₂, whereinCp represents a cyclopentadienyl ligand, M is Zr, Hf or Ti, and X is Clor CH₃). Unfortunately, however, although metallocenes do providesignificant advantages relative to the traditional Ziegler-Nattacatalysts, the high cost and difficulties associated withheterogenization of metallocenes, as well as the oxophilic nature of theearly transition metals, have limited the applicability of metallocenesas commercial polymerization catalysts.

[0005] Because polyolefins such as polyethylene and polypropylene aresuch important commercial polymers, there is an ongoing need forimproved polymerization techniques and polymerization catalysts.Recently, researchers have developed new catalysts suitable for olefinpolymerization that are complexes of late transition metals andsubstituted diimine ligands. Such catalysts are described, for example,in Bres et al., PCT Publication No. WO 98/49208, published Nov. 5, 1998.Other similar catalysts, comprised of diimine ligands and selectedmetals, are described in Bennett, PCT Publication No. WO 98/27174,published Jun. 25, 1998, and in Brookhart et al., PCT Publication No. WO98/30612, published Jul. 16, 1998.

[0006] A variety of catalyst systems have been used in the creation of“multimodal” polymer compositions, i.e., compositions containing two ormore molecular weight distributions as may be determined, for example,by the appearance of two or more peaks in a gel permeation chromatogramor the like. The term “multimodality” can also refer to othercharacteristics of a polymer composition as well, e.g., compositionaldistribution (the distribution of comonomers within a copolymer),tacticity distribution (wherein a polymer composition contains at leasttwo segments of differing tacticity, long-chain branching distribution,and the like. Such multimodal polymers are frequently more useful thancompositions that are not; for example, multimodal polymer compositionscan have improved Theological behavior, higher mechanical strength andincreased elasticity relative to corresponding compositions that are notmultimodal.

[0007] Several processes are known for preparing multimodal polymercompositions using the catalyst systems discussed above. In U.S. Pat.No. 5,032,562 to Lo et al., a process involving the use of tandemreactors operated in series is described wherein, in a first reactor, anolefinic monomer is catalytically polymerized in the presence ofhydrogen, with the product then transferred to a second reactor in whichpolymerization is conducted in the presence of hydrogen. In this way, ahigher molecular weight polymer is produced in the first reactor, andthe lower molecular weight polymer is produced in the second reactor.

[0008] U.S. Pat. No. 5,525,678 to Mink et al. provides a supportedcatalyst composition for producing a polyolefin resin having a highmolecular weight component and a low molecular weight component, whereinthe catalyst composition contains a first catalyst that is a metalloceneand a second catalyst that is a non-metallocene. The ratio of the highmolecular weight and low molecular weight components in the polymericproduct is determined by the ratio of the concentration of the twometals in the two-component catalyst composition. In addition, U.S. Pat.No. 4,659,685 to Coleman, III et al. Describes a two-component catalystcomposition for preparing polyolefins having a molecular weightdistribution which is multimodal, the catalyst composition comprising amixture of a supported titanium compound and a separately supported ornon-supported organometallic compound.

[0009] U.S. Pat. No. 5,032,562 to Lo et al., cited above, also relatesto a supported olefin polymerization catalyst composition for producinghigh density polyethylene (“HDPE”) having a multimodal molecular weightdistribution. The catalyst composition comprises: (1) a catalystprecursor supported on a porous carrier, and (2) a catalyst activator inthe form of a mixture of conventional Ziegler-Natta cocatalysts.Katayama et al., “The Effect of Aluminum Compounds in theCopolymerization of Ethylene/α-Olefins,” in Macromol. Symp. 97:109-118(1995), describes a similar system for preparing a polymer compositionhaving a bimodal composition using a two-component catalyst comprised ofa metallocene (Cp₂ZrCl₂) and either [Ph₃C⁺][B(C₆F₅)₄ ⁻] or[PhMe₂NH⁺][B(C₆F₅)₄ ⁻].

[0010] PCT Publication No. WO 92/00333, inventors Canich et al., and EP416,815, inventors Stevens et al., are also of interest insofar as thereferences describe metallocene catalysts for preparing polyolefins.Canich et al. describes metallocene catalyst compositions for producinghigh molecular weight polyolefins having a relatively narrow molecularweight distribution, wherein the catalyst composition is comprised of(1) a metallocene containing a Group IVB transition metal coordinated toa cyclopentadienyl ligand, and (2) a coordination complex such as ananionic complex containing a plurality of boron atoms, which serves as acatalyst activator. The metallocene catalysts described may bemononuclear or binuclear (i.e., containing one or two metal atoms whichserve as the active sites); the binuclear compounds dissociate duringpolymerization. Stevens et al. also pertains to metallocene catalysts toprepare addition polymers, particularly homopolymers and copolymers ofolefins, diolefins, “hindered” aliphatic vinyl monomers and vinylidenearomatic monomers. The Stevens et al. catalysts are metal coordinationcomplexes having constrained geometry, and are used in conjunction witha cocatalyst compound to form a complete catalytic system. Theconstrained geometry of the catalysts is stated to be of key importanceinsofar as the metal atom in the metallocene presumably is a more“exposed” active site.

[0011] Thus, the art provides metallocene catalyst compositions forproducing polymers, particular polyolefins, that have a multimodalmolecular weight distribution. However, such prior catalysts andcatalyst compositions either require two or more components, e.g., twocatalysts used in combination, or involve binuclear compounds that breakapart into two separate components during the polymerization process (asin the bimetallic catalyst disclosed by Canich et al.), giving rise topotential manufacturing problems, e.g., phase separation or the like,and/or loss of control over the molecular weight distribution of thepolymer composition prepared. In addition, the known metallocenecatalysts can be relatively difficult and time-consuming to synthesize,requiring expensive equipment, extreme reaction conditions, andmulti-step processes that ultimately result in a low yield of thedesired product.

[0012] Accordingly, there is a need in the art for a simpler way ofcatalytically preparing multimodal polymer compositions while avoidingthe high cost and difficulties associated with prior processes. An idealmethod for preparing a multimodal polymeric product would involve asingle catalyst that does not require the presence of a second catalyst,that retains its structure during the polymerization process, and isrelatively simple to synthesize. The present invention is directed tosuch a catalyst.

[0013] The novel catalyst is comprised of an organometallic complexhaving two or more different active sites, at least one of which iscomposed of a transition metal atom coordinated to an unsaturatednitrogenous compound such as an imine, diimine or a2,2′-bipyridine-containing compound. Use of such catalysts providenumerous advantages relative to the multimodal polymerization catalystof the prior art, in that they:

[0014] 1) allow for a exceptional control over the final polymercomposition;

[0015] 2) produce uniform multimodal products;

[0016] 3) can be constructed via a straightforward, low cost synthesis;

[0017] 4) are highly active polymerization catalysts;

[0018] 5) can be used to catalyze reactions other than polymerizationreactions, e.g., hydrogenation

[0019] 6) enable preparation of commodity polymers such as linear lowdensity polyethylene and isotactic polypropylene;

[0020] 7) can be used as either supported or homogeneous polymerizationcatalysts;

[0021] 8) are quite versatile and can be used in conjunction with avariety of monomer types; and

[0022] 9) provide for all of the advantages typically associated withmetallocene catalysts, i.e., versatility and use in conjunction with avariety of monomer types, the ability to control the degree of vinylunsaturation in the polymeric product, and the like.

[0023] The invention thus represents a significant advance in the fieldof catalysis, as prior to the development of the catalysts disclosed andclaimed herein, only a few of the aforementioned advantages could beachieved with a single catalyst system.

SUMMARY OF THE INVENTION

[0024] Accordingly, it is a primary object of the invention to provide acompound useful as a polymerization catalyst having two or moredifferent active sites, at least one of which is comprised of a metalatom coordinated to an unsaturated nitrogenous ligand such as an imine,diimine or a 2,2′-bipyridine-containing compound.

[0025] It is a further object of the invention to provide a catalystsystem which utilizes such a compound.

[0026] It is a further object of the invention to provide such compoundswhich are useful for preparing polyolefins or other polymers derivingfrom the polymerization of addition polymerizable monomers containingone or more degrees of unsaturation.

[0027] It is a still further object of the invention to provide a methodfor making an array of such compounds.

[0028] Additional objects, advantages and novel features of theinvention will be set forth in part in the description which follows,and in part will become apparent to those skilled in the art uponexamination of the following, or may be learned by practice of theinvention.

[0029] In a first embodiment, then, novel compounds are providedcomprised of multinuclear organometallic complexes, i.e., complexeshaving at least two active sites and associated organic ligands. Theactive sites have transition metal centers. The complex comprises anunsaturated nitrogenous compound, e.g., an imine, diimine or a2,2′-bipyridine-containing compound, chelating the first transitionmetal center, with a second transition metal center chelated with eithera second unsaturated nitrogenous compound or a cyclopentadienyl ligand.Additional metal centers may be present as well. Examples of suitableunsaturated nitrogenous ligands are those that contain a firstcoordinating atom that is a nitrogen atom contained within a C═N group,and a second coordinating atom that is either a second nitrogen atom,that may or may not be present in a second C═N group, or an oxygen,sulfur or phosphorus atom.

[0030] In another embodiment, the novel compounds are organometalliccomplexes comprising a first active site comprised of a transition metalatom M¹, and an unsaturated nitrogenous ligand having the structure offormula (I)

[0031] and a second active site comprised of a metal atom M², wherein M²is coordinated either to an unsaturated nitrogenous ligand having thestructure of formula (I) or to one or more cyclopentadienyl moieties(II)

[0032] wherein:

[0033] q is an optional double bond;

[0034] X is N, O, S or P, with the provisos that (a) when X is N or P,then either n is 1 or q is present as a double bond, but not both, and(b) when X is O or S, then n is zero and q is absent;

[0035] R¹, R⁶, and R⁷ are independently hydrido, hydrocarbyl orsubstituted hydrocarbyl, and R² and R⁵ are independently hydrido, halo,hydrocarbyl or substituted hydrocarbyl, or R¹ and R² and/or R⁵ and R⁶may be taken together to form a linkage —Q*—, resulting in a five- orsix-membered cyclic group, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— in whicha* is 2, 3 or 4, Z is N, O or S, b* is zero, 1 or 2, the sum of a* andb* is 3 or 4, and R* is selected from the group consisting of hydrido,halo, hydrocarbyl, hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹, and NO₂wherein R⁸ and R⁹ are each independently hydrocarbyl, or wherein R*moieties on adjacent carbon atoms may be linked to form an additionalfive- or six-membered ring, or R² and R⁵ may together form a linkage—Q*— as just defined;

[0036] R³ and R⁴ are independently selected from the group consisting ofhydrido and hydrocarbyl;

[0037] l is zero or 1;

[0038] m and n are independently zero or 1, preferably both zero; and

[0039] R and R′ are independently selected from the group consisting ofhalogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbyl substituted with one ormore halogen atoms, and C₁-C₂₄ hydrocarbyl-substituted Group IVBelements, x is 0, 1, 2, 3 or 4, and y is 0, 1, 2, 3 or 4, with theproviso that the sum of x and y cannot exceed 4, or, when R and R′ areortho to each other and x and y are each 1 or greater, R and R′ they cantogether form a five- or six-membered cyclic structure optionallysubstituted with one to four substituents selected from the groupconsisting of halogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄hydrocarbyl-substituted Group IVB elements.

[0040] In general, the aforementioned organic complexes may berepresented by the structural formula (III)

[0041] wherein:

[0042] B is a covalent bridging group comprising carbyl, silyl, disilyl,germanyl, ammonium, phosphonium,

[0043]  or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterocarbylene radical optionallycontaining a Group IVB element, a Group VB element, or both a Group IVBelement and a Group VB element, and is capable of binding up to n_(max)substituents through single covalent bonds, wherein n_(max) is at least4;

[0044] R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X, l, m, n and q are as defined abovewith respect to formula (I), and R, R′, x and y are as defined abovewith respect to formula (II);

[0045] Q¹, Q², Q³ and Q⁴ are independently selected from the groupconsisting of univalent radicals;

[0046] Q⁵ is an optional ligand having the structure of formula (I);

[0047] The subscript k is zero or 1;

[0048] M¹ is a transition metal;

[0049] M² is a Group IIIA element, a Group IVA element, a Group VAelement, a lanthanide, or an actinide;

[0050] Q is cyclopentadienyl, indenyl, fluorenyl, indolyl,aminoboratobenzyl, unsubstituted or substituted with R and/or R¹substituents as above, or Q may be J(R^(x))_(z-2) wherein J is anelement with a coordination number of three from Group VB or an elementwith a coordination number of two from Group VIB, R^(x) is selected fromthe group consisting of hydrogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄ alkoxy, and z isthe coordination number of J, and further wherein Q substituents ondifferent Z groups are linked through a C₁-C₃₀ hydrocarbylene bridge,

[0051] a is at least 1, b is 0, 1 or 2, and the sum of a and b is 2 or3.

[0052] The complex may also contain additional BL¹ and/or BL² moieties.

[0053] In a related embodiment, the novel compounds are organometalliccomplexes comprising a first active site comprised of a transition metalatom M¹ and a 2,2′-bipyridine-containing ligand having the structure offormula (IV)

[0054] and a second active site comprised of either a metal atom M²,wherein M² is coordinated to one or more cyclopentadienyl ligands offormula (II), or a transition metal atom M¹, wherein M¹ is coordinatedto an unsaturated nitrogenous ligand having the structure of formula(I), i and j are independently zero, 1, 2 or 3, and R¹⁰, R¹¹, R¹² andR¹³ are independently hydrido, hydrocarbyl or substituted hydrocarbyl.

[0055] In general, the aforementioned organic complexes may berepresented by the structural formulas (V), (VI), (VII), (VIII) and (IX)

[0056] wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X, l, m, n and q, are asdefined above with respect to formula (I), R, R′, x and y are as definedabove with respect to formula (II), and a, b, M¹, M², Q, Q¹, Q², Q³ andQ⁴ are as defined above with respect to formula (III);

[0057] Q⁵ and Q⁶ are optional ligands having the structure of formula(I); and

[0058] k and h are independently zero or 1;

[0059] These complexes may also contain additional BL¹ and/or BL²moieties.

[0060] In another embodiment of the invention, a catalyst system isprovided comprised of (1) a compound of the invention, as a catalyst,and (2) a catalyst activator, typically an aluminum-containing orboron-containing material. An exemplary catalyst is activator is methylaluminoxane (“MAO”). When used in catalyzing polymerization, thecatalyst system will be combined with an inert diluent, e.g., ahydrocarbon solvent, and optional additives such as polymerization rateaccelerators.

[0061] An additional embodiment of the invention provides a method forpreparing an polymer utilizing the catalyst system of the invention. Themethod comprises contacting selected addition polymerizable monomershaving at least one degree of unsaturation with the inventive catalystsystem under polymerization conditions effective to provide the desiredpolymer composition or other product.

[0062] With respect to the preparation of polyolefins, such polymers, asis known in the art, can be prepared having a variety of stericconfigurations deriving from the manner in which each monomer is addedto the growing polymer chain. Four basic configurations are commonlyrecognized for polyolefins: atactic, in which monomer orientation israndom; isotactic, in which each monomer is incorporated into thepolymer in the same configuration; syndiotactic, in which theconfiguration of monomers alternates along a polymer chain; andhemi-isotactic, in which unique and regularly repeatingstereochemistries are present within a single polymer chain. The presentcatalysts are useful for preparing polymers of desired tacticity,insofar as chiral catalysts can be used to catalyze stereospecificpolymerization. Generally, a transition metal center having C₂ symmetrywill give rise to isotactic polymers, while those catalysts having C_(s)symmetry will give rise to syndiotactic polymers.

[0063] In addition to their utility as polymerization catalysts, thenovel compounds are also useful in catalyzing other types of reactions,e.g., hydrogenation, dehydrocoupling, cyclization, substitution,carbomagnesation and hydrosilylation.

DETAILED DESCRIPTION OF THE INVENTION

[0064] Definitions and Nomenclature:

[0065] Before the present compounds, compositions and methods aredisclosed and described, it is to be understood that unless otherwiseindicated this invention is not limited to specific molecularstructures, ligands, or the like, as such may vary. It is also to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to belimiting.

[0066] It must be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to “a substituent” includes one or more substituents,reference to “a ligand” includes one or more ligands, and the like.

[0067] The term “alkyl” as used herein refers to a branched orunbranched saturated hydrocarbon group of 1 to approximately 24 carbonatoms, typically 1 to approximately 12 carbon atoms, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, octyl, decyl,tetradecyl, hexadecyl, eicosyl, tetracosyl and the like, as well ascycloalkyl groups such as cyclopentyl, cyclohexyl and the like. The term“lower alkyl” intends an alkyl group of 1 to 6 carbon atoms, preferably1 to 4 carbon atoms.

[0068] The term “alkylene” as used herein refers to a difunctionalsaturated branched or unbranched hydrocarbon chain containing from 1 toapproximately 24 carbon atoms, typically 1 to approximately 12 carbonatoms, and includes, for example, methylene (—CH₂—), ethylene(—CH₂—CH₂—), propylene (—CH₂—CH₂—CH₂—), 2-methylpropylene(—CH₂—CH(CH₃)—CH₂—), hexylene (—(CH₂)₆—), and the like. “Lower alkylene”refers to an alkylene group of 1 to 6, more preferably 1 to 4, carbonatoms.

[0069] The term “alkenyl” as used herein refers to a branched orunbranched hydrocarbon group of 2 to approximately 24 carbon atoms,typically 2 to approximately 12 carbon atoms, containing at least onecarbon-carbon double bond, such as ethenyl, n-propenyl, isopropenyl,n-butenyl, isobutenyl, t-butenyl, octenyl, decenyl, tetradecenyl,hexadecenyl, eicosenyl, tetracosenyl and the like. Preferred alkenylgroups herein contain 2 to 12 carbon atoms and 2 to 3 carbon-carbondouble bonds. The term “lower alkenyl” intends an alkenyl group of 2 to6 carbon atoms, preferably 2 to 4 carbon atoms, containing one —C═C—bond. The term “cycloalkenyl” intends a cyclic alkenyl group of 3 to 8,preferably 5 or 6, carbon atoms.

[0070] The term “alkenylene” refers to a difunctional branched orunbranched hydrocarbon chain containing from 2 to approximately 24carbon atoms, typically 2 to approximately 12 carbon atoms, and at leastone carbon-carbon double bond. “Lower alkenylene” refers to analkenylene group of 2 to 6, more preferably 2 to 5, carbon atoms,containing one —C═C— bond.

[0071] The term “alkynyl” as used herein refers to a branched orunbranched hydrocarbon group of 2 to approximately 24 carbon atoms, asabove containing at least one —C≡C— bond, such as ethynyl, n-propynyl,isopropynyl, n-butynyl, isobutynyl, t-butynyl, octynyl, decynyl and thelike. Preferred alkynyl groups herein contain 2 to 12 carbon atoms. Theterm “lower alkynyl” intends an alkynyl group of 2 to 6, preferably 2 to4, carbon atoms, and one —C≡C— bond.

[0072] The term “alkynylene” refers to a difunctional branched orunbranched hydrocarbon chain containing from 2 to approximately 24carbon atoms as before and at least one carbon-carbon triple bond.“Lower alkynylene” refers to an alkynylene group of 2 to 6, morepreferably 2 to 5, carbon atoms, containing one —C≡C— bond.

[0073] The term “alkoxy” as used herein intends an alkyl group boundthrough a single, terminal ether linkage; that is, an “alkoxy” group maybe defined as —OR where R is alkyl as defined above. A “lower alkoxy”group intends an alkoxy group containing one to six, more preferably oneto four, carbon atoms.

[0074] The term “array” used herein refers to a regular, orderly, two orthree dimensional arrangements of compounds. Arrays typically comprisefrom 2 to 1,000,000,000 features.

[0075] The term “aryl” as used herein refers to an aromatic speciescontaining 1 to 5 aromatic rings, either fused or linked, and eitherunsubstituted or substituted with 1 or more substituents typicallyselected from the group consisting of —(CH₂)_(x)—NH₂, —(CH₂)_(x)—COOH,—NO₂, halogen, alkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy,alkylthio, aryl, aralkyl, and the like, where x is an integer in therange of 0 to 6 inclusive as outlined above. Preferred aryl substituentscontain 1 to 3 fused aromatic rings, and particularly preferred arylsubstituents contain 1 aromatic ring or 2 fused aromatic rings. Theterms “aralkyl” and “alkaryl” refer to moieties containing both alkyland aryl species, typically containing less than about 24 carbon atoms,and more typically less than about 12 carbon atoms in the alkyl segmentof the moiety, and typically containing 1 to 5 aromatic rings. The term“aralkyl” refers to aryl-substituted alkyl groups, while the term“alkaryl” refers to alkyl-substituted aryl groups. The terms“aralkylene” and “alkarylene” are used in a similar manner to refer toaryl-substituted alkylene and alkyl-substituted arylene moieties.

[0076] The term “arylene” refers to a difunctional aromatic moiety;“monocyclic arylene” refers to a cyclopentylene or phenylene group.These groups may be substituted with up to four ring substituents asoutlined above.

[0077] The term “heterocyclic” refers to a five- or six-memberedmonocyclic structure or to an eight- to eleven-membered bicyclicstructure which is either saturated or unsaturated. Each heterocycleconsists of carbon atoms and from one to four heteroatoms selected fromthe group consisting of nitrogen, oxygen and sulfur. As used herein, theterms “nitrogen heteroatoms” and “sulfur heteroatoms” include anyoxidized form of nitrogen and sulfur, and the quaternized form of anybasic nitrogen. Examples of heterocyclic groups include piperidinyl,pyrazinyl, morpholinyl and pyrrolidinyl.

[0078] “Halo” or “halogen” refers to fluoro, chloro, bromo or iodo, andusually relates to halo substitution for a hydrogen atom in an organiccompound. Of the halos, chloro and fluoro are generally preferred.

[0079] “Hydrocarbyl” refers to univalent hydrocarbyl radicals containing1 to about 30 carbon atoms, preferably 1 to about 20 carbon atoms, mostpreferably 1 to about 12 carbon atoms, including branched or unbranched,saturated or unsaturated species, such as alkyl groups, alkenyl groups,aryl groups, and the like. The term “lower hydrocarbyl” intends ahydrocarbyl group of 1 to 6 carbon atoms, preferably 1 to 4 carbonatoms. The term “hydrocarbylene” intends a divalent hydrocarbyl moietycontaining 1 to about 30 carbon atoms, preferably 1 to about 24 carbonatoms, most preferably 1 to about 12 carbon atoms, including branched orunbranched, saturated or unsaturated species, or the like. The term“lower hydrocarbylene” intends a hydrocarbylene group of one to sixcarbon atoms, preferably one to four carbon atoms. “Substitutedhydrocarbyl” refers to hydrocarbyl substituted with one or moresubstituent groups, and the terms “heteroatom-containing hydrocarbyl”and “heterohydrocarbyl” refer to hydrocarbyl in which at least onecarbon atom is replaced with a heteroatom. Similarly, “substitutedhydrocarbylene” refers to hydrocarbylene substituted with one or moresubstituent groups, and the terms “heteroatom-containing hydrocarbylene”and “heterohydrocarbylene” refer to hydrocarbylene in which at least onecarbon atom is replaced with a heteroatom.

[0080] By “substituted” as in “substituted hydrocarbyl” or “substitutedhydrocarbylene” is meant that the hydrocarbyl or hydrocarbylene groupcontains one or more substituent groups which are inert under theprocess conditions to which the compound containing these groups issubjected. “Monosubstituted” refers to a hydrocarbyl or hydrocarbylenegroup having one substituent group and “disubstituted” refers to ahydrocarbyl or hydrocarbylene group containing two substituted groups.The substituent groups also do not substantially interfere with theprocess. Included in the meaning of “substituted” are heteroaromaticrings. Examples of substituents include, but are not limited to, amino(including primary amino and alkyl-substituted, typically loweralkyl-substituted, secondary and tertiary amino), alkyl (typically loweralkyl), alkoxy (typically lower alkoxy), alkenyl (typically loweralkenyl), aryl (e.g., phenyl), halo, haloalkyl, imino, nitro, and thelike.

[0081] A “substrate” refers to a material having a rigid or semi-rigidsurface. In some embodiments, at least one surface of the substrate willbe substantially flat. In other embodiments, the substrate will bedivided into physically separate synthesis regions. Division of thesubstrate into physically separate synthesis regions can be achievedwith, for example, dimples, wells, raised regions, etched trenches, orthe like. In some embodiments, small beads or pellets may be provided onthe surface by, for example, placing the beads within dimples, wells orwithin or upon other regions of the substrate's surface. Alternatively,the small beads or pellets may themselves be the substrate. Anappropriate substrate can be made out of any material which iscompatible with the process intended to occur thereon. Such materialsinclude, but are not limited to, organic and inorganic polymers, quartz,glass, silica, etc. The choice of an appropriate substrate for certaingiven conditions will be apparent to those of skill in the art.

[0082] The term “synthesis support” as used herein refers to a materialsuch as, for example, silica, alumina, a resin or controlled pore glass(CPG) which is functionalized to allow a ligand or a ligand component tobe attached either reversibly or irreversibly there to. A synthesissupport can be held within or upon a “substrate.” “Synthesis support,”“support,” “bead,” and “resin” are used interchangeably herein.

[0083] The term “unsaturated nitrogenous compound” refers to a compoundhaving a C═N moiety. Unsaturated nitrogenous compounds herein includeboth a true imine wherein the C═N moiety is present in an acyclicmolecular segment, as well as nitrogenous heterocycles in which thecarbon-nitrogen bond is present in an aromatic ring, e.g., as inpyridine, pyrimidine, pyrazine, and the like.

[0084] “Optional” or “optionally” means that the subsequently describedevent or circumstance may or may not occur, and that the descriptionincludes instances where said event or circumstance occurs and instanceswhere it does not. For example, the phrase “optionally substitutedhydrocarbyl” means that a hydrocarbyl moiety may or may not besubstituted and that the description includes both unsubstitutedhydrocarbyl and hydrocarbyl where there is substitution.

[0085] A “heterogeneous” catalyst as used herein refers to a catalystwhich is supported on a carrier, typically although not necessarily asubstrate comprised of an inorganic, solid, particulate porous materialsuch as silicon and/or aluminum oxide.

[0086] A “homogeneous” catalyst as used herein refers to a catalystwhich is not supported but is simply admixed with the initial monomericcomponents in a suitable solvent.

[0087] By “stereospecific” is meant a catalyst that will provide apolymer of predetermined, desired stereoregularity. The preferredcatalysts herein are “stereospecific.” By “isospecific” is meant acatalyst that will provide an isotactic polymer. By “syndiospecific” ismeant a catalyst that will provide a syndiospecific polymer. The mostpreferred catalysts herein are “isospecific” and “syndiospecific.”

[0088] The term “multimodal molecular weight distribution” as usedherein, and as alluded to above, refers to a polymer composition havingtwo or more molecular weight distributions, as may be determined, forexample, by the appearance of two or more peaks in a gel permeationchromatogram. Unless otherwise specified herein, the term “multimodal”is intended to encompass the term “bimodal.” By the process of theinvention, polymer compositions having a “multimodal” molecular weightdistribution can be generated using a multinuclear complexes oftransition metals coordinated to at least one unsaturated nitrogenousligand, in which polymerization takes place at different propagationrates at different active sites within the catalyst structure, orwherein the different active sites give rise to different terminationrates, and/or wherein the different active sites have differentresponses to H₂ (or other chain transfer agents). While theterm“multimodality” generally refers to a multimodal molecular weightdistribution, it should be emphasized that a polymer composition canalso be “multimodal” with respect to compositional distribution,tacticity distribution, long-chain branching distribution, or the like.

[0089] As used herein all reference to the Periodic Table of theElements and groups thereof is to the version of the table published bythe Handbook of Chemistry and Physics, CRC Press, 1995, which uses theIUPAC system for naming groups.

[0090] The Novel Compounds:

[0091] In a first embodiment, then, the novel compounds can be generallyrepresented by the formula (L¹)_(a)B(L²)_(b). They compounds aremultinuclear organometallic complexes, i.e., complexes having at leasttwo active sites and associated organic ligands. The complexes comprisean unsaturated nitrogenous ligand chelating a first transition metalcenter, with a second metal center chelated with either an unsaturatednitrogenous ligand or a cyclopentadienyl-based ligand. Additional metalcenters may be present as well, along with additional unsaturatednitrogenous ligands and/or cyclopentadienyl-based ligands. Unsaturatednitrogenous ligands contain a first coordinating atom that is a nitrogenatom contained within a C═N group, and a second coordinating atom thatis either a second nitrogen atom, which may or may not be present in asecond C═N group, or an oxygen, sulfur or phosphorus atom. Each C═Ngroup may be a true imine functionality contained within an acyclicmolecular segment, or may represent a linkage within a heterocycle suchas a pyridine or pyrimidine ring.

[0092] Exemplary complexes are represented by structural formula (III)

[0093] wherein:

[0094] B is a covalent bridging group comprising carbyl, silyl, disilyl,germanyl, ammonium, phosphonium,

[0095]  or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterohydrocarbylene radicaloptionally containing a Group IVB element, a Group VB element, or both aGroup IVB element and a Group VB element, and is capable of binding upto n_(max) substituents through single covalent bonds, wherein n_(max)is at least 4. Preferred B groups are C₁-C₃₀ hydrocarbylene, substitutedhydrocarbylene, heterohydrocarbylene or substituted heterohydrocarbyleneradicals optionally containing a Group IVB element and/or a Group VBelement, and particularly preferred B groups are aryl C₁-C₃₀heterohydrocarbylene groups, and silicon.

[0096] The cyclopentadienyl moiety, as shown, is optionally substitutedwith R and R′ groups. Specifically, the integers x and y areindependently 0, 1, 2, 3 or 4, with the proviso that the sum of x and ycannot exceed 4; preferably, x and y are independently 0, 1 or 2, andmost preferably are 0 or 1. R and R′ can be halogen, C₁-C₂₄ hydrocarbyl,either unsubstituted or substituted with one or more halogen atoms,lower alkyl groups and/or Group IVB elements. Alternatively, when an Rand an R′ substituent are both present, and ortho to each other on thecyclopentadienyl ring, they may together form a five- or six-memberedcyclic structure. This cyclic structure may be unsubstituted orsubstituted with a halogen or C₁-C₂₄ hydrocarbyl group as explainedabove. Preferred R and R′ substituents are halogen and C₁-C₂₄ alkyl;complexes wherein R and R′ are ortho to each other and linked to form acyclopentadienyl or indenyl group, either unsubstituted or substitutedwith halogen and/or lower alkyl moieties, are also preferred.Particularly preferred R and R′ groups are halogen and lower alkyl;complexes wherein R and R′ are ortho to each other and linked to form acyclopentadienyl ring optionally substituted with a lower alkyl groupare also particularly preferred.

[0097] Q is cyclopentadienyl, indenyl, fluorenyl, indolyl oraminoboratobenzyl, and may be unsubstituted or substituted with R and/orR¹ substituents as above. Alternatively, Q is J(R^(x))_(z-2) wherein Jis an element with a coordination number of three from Group VB or anelement with a coordination number of two from Group VIB, R^(x) isselected from the group consisting of hydrogen, C₁-C₂₄ hydrocarbyl,C₁-C₂₄ hydrocarbyl substituted with one or more, typically one totwelve, halogen atoms, and C₁-C₂₄ alkoxy, and z is the coordinationnumber of J. Preferred Q substituents are cyclopentadienyl, indenyl,fluorenyl, aminoboratobenzyl or J(R^(x))_(z-2) wherein J is nitrogen,phosphorus, oxygen or sulfur, and R^(x) is C₁-C₁₂ alkyl optionallysubstituted with one or more, typically one to six, halogen atoms.Particularly preferred Q groups are NR^(x) moieties wherein R^(x) islower alkyl or phenyl.

[0098] Q¹, Q², Q³ and Q⁴ are each a univalent radical, and arepreferably independently selected from the group consisting of hydrido,halide, alkoxy, amido, and substituted or unsubstituted C₁-C₃₀hydrocarbyl; if substituted, the substituents are typically although notnecessarily electron-withdrawing groups such as a halogen atom, analkoxy group, or the like, or the substituents may be Group IVB or GroupVB elements. Alternatively, Q¹ and Q² and/or Q³ and Q⁴ may together forman alkylidene olefin (i.e., ═CR₂ wherein R is hydrogen or hydrocarbyl,typically lower alkyl), acetylene, or a five- or six-membered cyclichydrocarbyl group. Preferred Q¹, Q², Q³ and Q⁴ moieties are hydrido,amido, C₁-C₁₂ alkyl, and C₁-C₁₂ alkyl substituted with one or morehalogen and/or alkoxy groups, typically one to six such groups, andC₁-C₁₂ alkyl substituted with a Group IVB element. Particularlypreferred Q¹, Q², Q³ and Q⁴ moieties are hydrido, amido, lower alkyl andlower alkoxy.

[0099] Q⁵ is an optional ligand having the structure of formula (I).

[0100] The subscripts k, l, m and n are independently zero or 1,preferably both m and n are zero, and letter “q” represents an optionaldouble bond.

[0101] X is N, O, S or P, with the provisos that (a) when X is N or P,then either n is 1 or q is present as a double bond, but not both, and(b) when X is O or S, then n is zero and q is absent.

[0102] R¹, R⁶ and R⁷ are independently hydrido, hydrocarbyl orsubstituted hydrocarbyl, as defined above, and R² and R⁵ areindependently hydrido, halo, hydrocarbyl or substituted hydrocarbyl, orR¹ and R² and/or R⁵ and R⁶ may be taken together to form a linkage —Q*—,resulting in a five- or six-membered cyclic group. As explained above,Q* is —[(CR*)_(a*)(Z)_(b*)]— in which a* is 2, 3 or 4, Z is N, O or S,b* is zero, 1 or 2, the sum of a* and b* is 3 or 4, and R* is selectedfrom the group consisting of hydrido, halo, hydrocarbyl, hydrocarbyloxy,trialkylsilyl, NR⁸ ₂, OR⁹, and NO₂, wherein R⁸ or R⁹ are eachindependently hydrocarbyl, or wherein R moieties on adjacent carbonatoms may be linked to form an additional five- or six-membered ring. R²and R⁵ may together form a linkage —Q*— as just defined. Preferably, R⁶is a substituted or unsubstituted aromatic group, e.g., phenyl,1-naphthyl, 2-naphthyl, 2-ethylphenyl, 2,6-diisopropylphenyl,2,6-di-n-butylphenyl, 2,6-dimethylphenyl, 2-t-butylphenyl,2,6-diphenylphenyl, 2,4,6-trimethylphenyl, 2-trifluoromethylphenyl,4-bromo-2,6-dimethylphenyl, 3,5-dichloro-2,6-diethylphenyl, or2,6-bis(2,6-dimethylphenyl)phenyl.

[0103] Examples of R¹, R⁶ and R⁷ thus include, but are not limited to,hydrido, methyl, ethyl, n-propyl, isopropyl, methoxy, ethoxy,isopropoxy, phenyl, benzyl, phenoxy, pyridyl, diisopropylphenyl,methoxyphenyl, trimethylsilyl, triethylsilyl, and the like; R² and R⁵substituents can include any of the foregoing as well as halogensubstituents, i.e., chloro, fluoro, bromo and iodo, with chloro andfluoro preferred. When R¹ and R² and/or R⁵ and R⁶ are linked, the cyclicstructures so formed may be alicyclic or aromatic, including, forexample, furanyl, pyrrolyl, thiophenyl, imidazolyl, pyrazolyl,oxathiolyl, pyridinyl, methylpyridinyl, ethylpyridinyl, pyridazinyl,pyrimidinyl, pyrazinyl, piperidinyl, piperazinyl, morpholinyl,tetrahydrothiophenyl, tetrahydrofuranyl, tetrahydropyranyl,1,4-dioxanyl, etc. When R² and R⁵ are linked, the resulting structuresare alicyclic and may or may not contain heteroatoms; such moietiesinclude, for example, cyclopentane, cyclohexane, tetrahydrofuran,tetrahydropyran, tetrahydrothiophene, 1,4-dioxane, 1,2-dithiole,1,3-dithiole, piperazine, morpholine, and the like.

[0104] R³ and R⁴ are independently selected from the group consisting ofhydrido and hydrocarbyl, preferably hydrido or lower alkyl, or at leastone of R³ and R⁴ may be bound through a lower alkylene linkage,preferably a methylene linkage, to an atom contained within L¹ or L².

[0105] M¹ is a transition metal, including, but not limited to, Mb, Ta,Mo, W, Mn, Re, V and Cr.

[0106] M² is a Group IIIA element, a Group IVA element, a Group VAelement, a lanthanide, or an actinide. Particularly preferred M²moieties are Zr, Hf and Ti.

[0107] The letter “a” represents an integer of at least 1, “b” is zero,1 or 2, and the sum of a and b is 2 or 3.

[0108] The complex may also contain additional BL¹ and/or BL² moieties.

[0109] One group of such compounds is represented by structural formula(V)

[0110] wherein:

[0111] a, b, B, M¹, M², R, R′, k, x, y, Q, Q¹, Q², Q³, Q⁴ and Q⁵ are asdefined above with respect to formula (III);

[0112] R¹⁰, R¹¹, R¹² and R¹³ are independently hydrido, hydrocarbyl orsubstituted hydrocarbyl; and

[0113] i and j are independently zero, 1, 2 or 3.

[0114] In another embodiment, complexes of the invention have thestructure of formula (VI)

[0115] R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X, a, b, B, M¹, k, l, m, n, q, Q¹,Q², Q³, Q⁴ and Q⁵ are as defined above with respect to formula (III);

[0116] Q⁶ is an optional ligand having the structure of formula (I);

[0117] h is zero or 1;

[0118] R¹⁰, R¹¹, R¹² and R¹³ are independently hydrido, hydrocarbyl orsubstituted hydrocarbyl; and

[0119] i and j are independently zero, 1, 2 or 3.

[0120] Another group of complexes is represented by structural formula(VII)

[0121] wherein:

[0122] a, b, B, M¹, M², R, R′, k, x, y, Q, Q¹, Q², Q³, Q⁴ and Q⁵ are asdefined above with respect to formula (III);

[0123] R¹² and R¹³ are independently hydrido, hydrocarbyl or substitutedhydrocarbyl; and

[0124] i and j are independently zero, 1, 2 or 3.

[0125] In still another embodiment, complexes of the invention have thestructure of formula (VIII)

[0126] wherein:

[0127] R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X, a, b, B, M¹, k, l, m, n, q, Q¹,Q², Q³, Q⁴ and Q⁵ are as defined above with respect to formula (III);

[0128] Q⁶ is an optional ligand having the structure of formula (I);

[0129] h is zero or 1;

[0130] R¹² and R¹³ are independently hydrido, hydrocarbyl or substitutedhydrocarbyl; and

[0131] i and j are independently zero, 1, 2 or 3.

[0132] In still another embodiment, complexes of the invention have thestructure of formula

[0133] wherein

[0134] R¹, R², R³, R⁴, R⁵, R⁶, R⁷, X, a, b, B, M¹, k, l, m, n, q, Q¹,Q², Q³, Q⁴ and Q⁵ are as defined above with respect to formula (III);

[0135] Q⁶ is an optional ligand having the structure of formula (I);

[0136] h is zero or 1;

[0137] R¹³ is independently hydrido, hydrocarbyl or substitutedhydrocarbyl; and

[0138] j is zero, 1, 2 or 3.

[0139] In yet another embodiment, complexes of the invention have thestructure of formula (IX)

[0140] wherein:

[0141] a, b, B, M¹, M², R, R′, k, x, y, Q, Q¹, Q², Q³, Q⁴ and Q⁵ are asdefined above with respect to formula (III);

[0142] R¹³ is independently hydrido, hydrocarbyl or substitutedhydrocarbyl; and

[0143] j is zero, 1, 2 or 3.

[0144] Specific catalysts encompassed by formulae (III), (V), (VI),(VII),(VIII), (IX) and (X) include, but are not limited to, thefollowing:

[0145] Synthesis:

[0146] The complexes of the invention may be prepared using relativelysimple and straightforward synthetic processes known to those skilled inthe art and/or described in the pertinent texts and literature. Forexample, the complexes may be prepared by first providing an unsaturatednitrogenous ligand, L^(n), which can be obtained commercially orchemically synthesized. See, e.g., PCT Publication Nos. WO 98/27124, WO98/30612 and WO 98/49208, and U.S. Pat. No. 5,866,663, which describesuch ligands and synthesis thereof. For example, an unsaturatednitrogenous ligand having the structural formula (XI)

[0147] wherein R^(d) and R^(e) are defined as any of R¹, R², R⁵ and R⁶,may be synthesized by addition of the primary amine R^(d)—NH₂ to thediketone of formula (XII)

[0148] in a simple, straightforward, one-step reaction.

[0149] Other unsaturated nitrogenous ligands may be synthesized in asimilar manner, by reaction of a suitable primary amine with a selectedaldehyde or a ketone. For example, the asymmetric ligand of formula(XIII)

[0150] may be readily synthesized from 2,6-diisopropylaniline and2-pyrazinecarboxaldehyde, as described, for example, in Weidenbruch etal. (1993) Organometallic Chemistry 454:35. Patai, The Chemistry of theCarbon-Nitrogen Double Bond (1970), also provides information on varioussynthetic methods that can be used in the preparation of unsaturatednitrogenous compounds.

[0151] The next step of the synthesis involves the use of a halogenatedcompound B(Hal)_(2(a+b)) as a starting material (wherein B, a and b areas defined earlier herein and “Hal” represents a halogen atom). Thecompound is contacted with an alkali metal salt of the desired secondligand L^(x), i.e., an unsaturated nitrogenous ligand or acyclopentadienyl-based ligand to provide an intermediate L^(n)_(a)B(Hal)_(b). Next, the intermediate is successively reacted with analkali metal salt of L^(n), thus providing the intermediate L^(n)_(a)BL^(x) _(b). This intermediate is deprotonated and metallated asdescribed below.

[0152] In an alternative method, a starting material B(Hal)₄ is causedto react with an alkali metal salt of the L^(n) ligand. The product isthen contacted with an alkali metal salt of an aromatic compound Ar,containing one to three cyclopentadienyl rings, either substituted orunsubstituted, to provide an intermediate L^(n)BAr₂. (When it is desiredthat the end product contain different aromatic groups, successivereaction with different aromatic salts is carried out, i.e.,L^(n)B(Hal)₂ is first reacted with an alkali metal salt of a firstaromatic species Ar₁, then with an alkali metal salt of a secondaromatic species Ar₂, and the like.) This intermediate is then used toprepare the compound L^(n) _(a)BL^(x) _(b). Metallation is then carriedout using metal complexes generally of the form MQ′Q′Y₂ wherein M is atransition metal Q′ is Q¹, Q², Q³ or Q⁴ as defined earlier herein, andthe Y substituents are leaving groups that are typically halide,pseudohalide (e.g., lower alkoxy such as methoxy),flurohydrocarbylborate, etc. During the metallation reaction, the Ygroups are eliminated.

[0153] Oxamides may also be used as starting materials. In this method,a oxallyl chloride is reacted with two equivalents of a primary amine inthe presence of THF. If desired, equal molar equivalents of differentprimary amines may be sequentially added. Once the oxamide has beensynthesized, it is reacted with PCl₃ or POCl₃ or the like to form abis-imidoylchloride. The bis-imidoylchloride ligand may then be reactedwith a diol bridging compound in the presence of triethylamine, a twomolar equivalent of sodium hydride, and THF to form a bridged ligandcomplex. This complex may then be metallated as discussed above. Othersuitable metallation reactions for preparing the present complexes willbe known to those skilled in the art and/or described in or readilyderived from the pertinent texts and literature.

[0154] Preparation of the Catalyst System:

[0155] The novel compounds of the invention, when used as polymerizationcatalysts, are used in conjunction with a conventional catalystactivator as will be appreciated by those skilled in the art. Thus,prior to use, the compounds of the invention are incorporated into acatalyst system that includes such an activator. Suitable catalystactivators include, but are not limited to, metal alkyls, hydrides,alkylhydrides, and alkylhalides, such as alkyllithium compounds,dialkylzinc compounds, trialkyl boron compounds, trialkylaluminumcompounds, alkylaluminum halides and hydrides, and tetraalkylgermaniumcompounds. Specific examples of useful activators includen-butyllithium, diethylzinc, di-n-propylzinc, triethylboron,triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum,ethylaluminum dichloride, dibromide and dihydride, isobutyl aluminumdichloride, dibromide and dihydride, di-n-propylaluminum chloride,bromide and hydride, diisobutyl-aluminum chloride, bromide and hydride,ethylaluminum sesquichloride, methyl aluminoxane (“MAO”), hexaisobutylaluminoxane, tetraisobutyl aluminoxane, polymethyl aluminoxane,tri-n-octylaluminum, tetramethyl germanium, and the like. Otheractivators that are typically referred to as ionic cocatalysts may alsobe used; such compounds include, for example, (C₆H₆)₃ ⁺, C₆H₅—NH₂CH₃ ⁺,and fluorohydrocarbylboron compounds such astetra(pentafluorophenyl)borate, sodiumtetrakis[(bis-3,5-trifluoromethyl)phenyl]borate, H⁺(OCH₂CH₃)₂[(bis-3,5-trifluoromethyl)-phenyl]borate,trityltetra(pentafluorophenyl)borate and tris(pentafluorophenyl)boron.Mixtures of activators may, if desired, be used. Generally, the catalystactivator is such that upon combination with a compound of theinvention, a catalytically active ionic species results.

[0156] For liquid phase or slurry polymerization, the catalyst andactivator are generally mixed in the presence of inert diluents such as,for example, aliphatic or aromatic hydrocarbons, e.g., liquified ethane,propane, butane, isobutane, n-butane, n-hexane, isooctane, cyclohexane,methylcyclohexane, cyclopentane, methylcyclopentane, cycloheptane,methylcycloheptane, benzene, ethylbenzene, toluene, xylene, kerosene,Isopar® M, Isopar® E, and mixtures thereof. Liquid olefins, or the like,which serve as the monomers or comonomers in the polymerization processmay also serve as the diluent; such olefins include, for example,ethylene, propylene, butene, 1-hexene and the like. The amount ofcatalyst in the diluent will generally be in the range of about 0.01 to1.0 mmoles/liter, with activator added such that the ratio of catalystto activator is in the range of from about 10:1 to 1:2000, preferably inthe range of from about 1:1 to about 1:200, on a molar basis.

[0157] Preparation of the catalyst/activator/diluent mixture is normallycarried out under anhydrous conditions in the absence of oxygen, attemperatures in the range of from about −90° C. to about 300° C.,preferably in the range of from about −10° C. to about 200° C.

[0158] The catalyst, activator and diluent are added to a suitablereaction vessel, in any order, although, as noted above, the catalystand activator are usually mixed in the diluent and the mixture thusprepared then added to the reactor.

[0159] A further embodiment of the invention provides a method ofsynthesizing arrays of metal-ligand compounds using the multimodalcatalysts of the invention. In the method at least two differentmetal-binding amino alcohol-derived ligands are synthesized on ordelivered to a substrate. These ligands may be supported or unsupportedprior to contact with the substrate. Once in contact with the substrate,the ligands are metallated, as described above, forming metal-ligandcompounds. Each of the ligands may be-metallated with the same ordifferent Group IV A, Group VA or Group VIA metals.

[0160] Preparation of Catalyst Arrays:

[0161] In a still further embodiment, methods are provided forsynthesizing and screening arrays of multimodal metal-ligand compounds.In the method at least two alkali metal salts of different L^(n)metal-binding, unsaturated nitrogenous ligands are synthesized on ordelivered to a substrate. These ligands may be supported or unsupportedprior to contact with the substrate. Once in contact with the substrate,the ligands are contacted with a halogenated compound B(Hal)_(2(a+b))(wherein B, a and b are as defined earlier herein and “Hal” represents ahalogen atom) to provide intermediate L^(n) _(a)B(Hal)_(b) compoundsNext, the intermediates are successively reacted with alkali metal saltsof the desired second ligands L^(x), i.e., unsaturated nitrogenousligands or a cyclopentadienyl-based ligands, thus providing intermediateL^(n) _(a)BL^(x) _(b) compounds. These intermediates are deprotonatedand metallated as described above. Each of the ligands may be metallatedwith the same or different Group IV A, Group VA or Group VIA metals. Themultimodal metal-ligand compounds may be activated using one or moreconventional catalyst activators.

[0162] In a still further embodiment, methods are provided for formingand screening arrays of multimodal metal-ligand compounds of theinvention. In the method at least two different multimodal metal-ligandcompounds are synthesized on a substrate. Again, these ligands may besupported or unsupported prior to contact with the substrate. Themultimodal metal-ligand compounds may be synthesized in an array or maybe placed in an array arrangement after synthesis. The multimodalmetal-ligand compounds may be screened for purity and identity usingconventional. Typical screening and characterizing techniques such asmass spectrometry, calorimetry, digital autoradiography, polarimetry,imaging polarimetry, infrared spectroscopy, reflectance spectroscopy,uv-vis spectroscopy, chemisorption, surface area (BET) measurements,uv-vis fluorescence, phosphorescence, chemiluminescence, Ramanspectroscopy, NIR spectroscopy, magnetic resonance imaging, NMRspectroscopy, Electron Spin Resonance (ESR) spectroscopy, gaschromatography, high performance liquid chromatography (HPLC), x-raydiffraction, neutron diffraction, refractometry, circular dichroism,electron spectroscopy, scanning electron microscopy (SEM), transmissionelectron microscopy (TEM), scanning tunneling microscopy (STM), and thelike.

[0163] The multimodal metal-ligand compounds may then be used incatalyzing reactions. During and after the catalyzed reactions, themultimodal metal-ligand compounds and the resulting products can bescreened for useful properties using conventional screening andcharacterizing techniques such as chemical or biological testing; massspectrometry; reaction calorimetry; parallel reaction calorimetry;parallel differential scanning calorimetry; viscosity measurement;digital autoradiography; thermal imaging; polarimetry; imagingpolarimetry; infrared spectroscopy; IR imaging; reflectancespectroscopy; uv-vis spectroscopy; chemisorption; surface area (BET)measurements; uv-vis fluorescence; phosphorescence; chemiluminescence;Raman spectroscopy; NIR spectroscopy; magnetic resonance imaging; NMRspectroscopy; gas chromatography; high performance liquid chromatography(HPLC); gel permeation chromatography (GPC); TREF; x-ray diffraction;neutron diffraction; refractometry; circular dichroism; turbidimetry;electron spectroscopy; scanning electron microscopy (SEM); transmittingelectron microscopy (TEM); scanning tunneling microscopy (STM).

[0164] The array of products can also be used to screen for importantchemical and physical properties such as solvent extractables,solubility, porosity, weatherability, uv-vis stability, scratchresistance, abrasion resistance, wettability, hardness, color,dielectric constant, moisture absorption, solvent swelling, gloss,adhesion, heat aging, shear, stain resistance, and scrub resistance.Screening may be performed either simultaneously, serially and/or in aspatially selective manner, i.e., wherein the detector used is distancedfrom the array, the array is screened and the detector is thenrepositioned so that a different portion of the array is screened.

[0165] Use In Polymerization:

[0166] The novel catalysts are used to prepare polymeric compositionsusing conventional polymerization techniques known to those skilled inthe art and/or described in the pertinent literature. The monomer(s),catalyst and catalyst activator are contacted at a suitable temperatureat reduced, elevated or atmospheric pressure, under an inert atmosphere,for a time effective to produce the desired polymer composition. Thecatalyst may be used as is or supported on a suitable support. In oneembodiment, the novel catalysts are used as homogeneous catalysts, i.e.,as unsupported catalysts, in a gas phase or liquid phase polymerizationprocess. A solvent may, if desired, be employed. The reaction may beconducted under solution or slurry conditions, in a suspension using aperfluorinated hydrocarbon or similar liquid, in the gas phase, or in asolid phase powder polymerization.

[0167] Liquid phase polymerization generally involves contacting themonomer or monomers with the catalyst/activator mixture in thepolymerization diluent, and allowing reaction to occur underpolymerization conditions, i.e., for a time and at a temperaturesufficient to produce the desired polymer product. Polymerization may beconducted under an inert atmosphere such as nitrogen, argon, or thelike, or may be conducted under vacuum. Preferably, polymerization isconducted in an atmosphere wherein the partial pressure of reactingmonomer is maximized. Liquid phase polymerization may be carried out atreduced, elevated or atmospheric pressures. In the absence of addedsolvent, i.e., when the olefinic monomer serves as the diluent, elevatedpressures are preferred. Typically, high pressure polymerization in theabsence of solvent is carried out at temperatures in the range of about0° C. to about 300° C., preferably in the range of about 50° C. to about200° C., and at pressures on the order of 1 to 5,000 atm, typically inthe range of about 10 to 500 atm. When solvent is added, polymerizationis generally conducted at temperatures in the range of about 0° C. toabout 200° C., preferably in the range of about 50° C. to about 100° C.,and at pressures on the order of 10 to 500 atm.

[0168] Polymerization may also take place in the gas phase, e.g., in afluidized or stirred bed reactor, using temperatures in the range ofapproximately 60° C. to 120° C. and pressures in the range ofapproximately 10 to 1000 atm.

[0169] The monomer or comonomers used are addition polymerizablemonomers containing one or more degrees of unsaturation. Olefinic orvinyl monomers are preferred, and particularly preferred monomers areα-olefins having from about 2 to about 20 carbon atoms, such as, forexample, linear or branched olefins including ethylene, propylene,1-butene, 3-methyl-1-butene, 1,3-butadiene, 1-pentene,4-methyl-1-pentene, 1-hexene, 4-methyl-1-hexene, 1,4-hexadiene,1,5-hexadiene, 1-octene, 1,6-octadiene, 1-nonene, 1-decene,1,4-dodecadiene, 1-hexadecene, 1-octadecene, and mixtures thereof.Cyclic olefins and diolefins may also be used; such compounds include,for example, cyclopentene, 3-vinylcyclohexene, norbornene,5-vinyl-2-norbomene, 5-ethylidene-2-norbornene, dicyclopentadiene,4-vinylbenzocyclobutane, tetracyclododecene,dimethano-octahydronaphthalene, and7-octenyl-9-borabicyclo-(3,3,1)nonane. Aromatic monomers that may bepolymerized using the novel metallocenes include styrene,o-methylstyrene, m-methylstyrene, p-methylstyrene, p-tert-butylstyrene,m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, indene,4-vinylbiphenyl, acenaphthalene, vinylfluorene, vinylanthracene,vinylphenanthrene, vinylpyrene and vinylchrisene. Other monomers thatmay be polymerized using the present catalysts includemethylmethacrylate, ethylacrylate, vinyl silane, phenyl silane,trimethylallyl silane, acrylonitrile, maleimide, vinyl chloride,vinylidene chloride, tetrafluoroethylene, isobutylene, carbon monoxide,acrylic acid, 2-ethylhexylacrylate, methacrylonitrile and methacrylicacid.

[0170] In gas and slurry phase polymerizations, the catalyst is used ina heterogeneous process, i.e., supported on an inert inorganicsubstrate. Conventional materials can be used for the support, and aretypically particulate, porous materials; examples include oxides ofsilicon and aluminum, or halides of magnesium and aluminum. Particularlypreferred supports from a commercial standpoint are silicon dioxide andmagnesium dichloride.

[0171] The polymeric product resulting from the aforementioned reactionmay be recovered by filtration or other suitable techniques. If desired,additives and adjuvants may be incorporated into the polymer compositionprior to, during, or following polymerization; such compounds include,for example, pigments, antioxidants, lubricants and plasticizers.

[0172] As explained earlier herein, the invention enables preparation ofpolymer compositions that are multimodal in nature, typically, but notnecessarily, having a multimodal molecular weight distribution. That is,the catalysts used herein contain two or more active sites at whichpropagation rates differ, or that have different temperaturesensitivities and/or H₂ responsiveness or the like. In this way, thetype and degree of multimodality in the polymeric product can becontrolled as desired. Multimodal polymer compositions are usefulinsofar as Theological behavior, mechanical strength and elasticity canbe improved relative to corresponding compositions that are notmultimodal.

[0173] The compounds of the invention are also useful in catalyzingother types of reactions, i.e., reactions other than polymerizations.Such reactions include, but are not limited to, hydrogenation,dehydrocoupling, cyclization, substitution, carbomagnesation andhydrosilylation. Methods for using the metal complexes of the inventionto catalyze the aforementioned reactions and others will be known tothose skilled in the art and/or described in the pertinent texts andliterature.

EXPERIMENTAL

[0174] It is to be understood that while the invention has beendescribed in conjunction with the preferred specific embodimentsthereof, that the foregoing description is intended to illustrate andnot limit the scope of the invention. Other aspects, advantages andmodifications within the scope of the invention will be apparent tothose skilled in the art to which the invention pertains.

[0175] All patents, patent applications, and publications mentionedherein are hereby incorporated by reference in their entireties.

Example 1

[0176] Synthesis of Multinuclear Compound

[0177] This example describes synthesis of a multinuclear compound ofthe invention, with synthesis of a imine-containing ligand described inpart (a), binding of the ligand to the covalent bridging group describedin part (b), metallation of the first imine-containing ligand describedin part (c) and metallation of the remaining ligand described in part(d).

[0178] (a) Synthesis of the imine-containing ligand: Theimine-containing ligand 1 may be synthesized as illustrated in Schemes 1and 2. First, diketone a is reacted with 2 equimolar amounts of b,2,6-dimethylphenylamine, in THF to form diamide 1,N,N′-bis(2,6-dimethylphenyl) ethane-1,2-diamide.

[0179] Second, as shown is Scheme 2, an approximately 2:1 molar ratiomixture of PCl₅ to oxamide 1, is stirred at reflux at 110° C. in toluenefor 3 hours. Crystallization of the crude reaction mixture from coldpentane yields the desired ligand 21,4-diaza-1,4-bis(2,6-dimethylphenyl)-2,3-dichlorobuta-1,3-butadiene

[0180] (b) Binding of the ligand to the covalent bridging group: Asdepicted in Scheme 3, an approximately 2:4:1 molar ratio mixture ofligand 2 to NaH, to bridging group 3,3,3,3′,3′-tetramethyl-1,1′-spirobisindane-5,5′,6,6′-tetrol (AldrichChemical), is stirred at 80° C. in NEt₃ and THF for 3 hours to form thebridged ligand compound 4.

[0181] (c) Metallation of the imine-containing ligand: One of theimine-containing ligands in the bridged compound is then metallated byreacting the compound 4 with an equal molar amount of ((DME)NiBr₂ indiethyl ether to form semi-metallated compound 5 as illustrated below inScheme 4.

[0182] (e) Metallation of the remaining ligand: The remaining ligand inthe bridged compound is then metallated by reacting the compound 5 withan equal molar amount of (COD)PdCl₂ slurried in diethylether to formmultinuclear compound 6 as illustrated in Scheme 5.

[0183] The mixture is then filtered and the solvent removed. The solidis washed with pentane and multinuclear compound 6 collected.

Example 2

[0184] Synthesis of Multinuclear Compound

[0185] This example describes an alternative synthesis of a multinuclearcompound of the invention. Synthesis of a first imine-containing ligandas described in Example 1. Formation of a second imine-containing ligandis described in part (a), binding of the first ligand to the bridginggroup is described in part (b), binding of the second ligand to thebridging group is described in part (c) and metallation of both ligandsis described in part (d).

[0186] (a) Formation of a second imine-containing ligand: A secondimine-containing ligand 8 may be synthesized as illustrated in Schemes 6and 7. First, oxallyl chloride a is reacted with 2 equivalents of2-t-butylaniline c, in THF to form diamide 7,N,N′-bis-(2-t-butylphenyl)ethane diamide.

[0187] Second, as shown is Scheme 7, an approximately 2:1 molar ratiomixture of PCl₅ to diamide 7, is stirred at reflux at 110° C. in toluenefor 3 hours. Crystallization of the crude reaction mixture from coldpentane yields the desired ligand 8

[0188] (b) Binding of the first ligand to the covalent bridging group:As depicted in Scheme 8, an approximately 1:2:1 molar ratio mixture ofligand 2, as prepared in Example 1, to NaH, to bridging group 3, isstirred at reflux at 80° C. in NEt₃ and THF for 3 hours to form thesemi-bridged ligand compound 9.

[0189] (c) Binding of the second ligand to the semi-bridged ligandcompound: As depicted in Scheme 9, an approximately 1:2:1 molar ratiomixture of ligand 8 to NaH, to semi-bridged ligand compound 9, isstirred at reflux in NEt₃ and THF for 3 hours to form the bridged ligandcompound 10.

[0190] (d) Metallation of the bridged ligand compound: Both of theimine-containing ligands in the bridged compound are then metallated byreacting the compound 10 with a 2:1 molar amount of ((DME)NiBr₂ indiethylether to form multinuclear compound 11 as illustrated below inScheme 10.

[0191] The mixture is then filtered and the solvent removed. The solidis washed with pentane and multinuclear compound 11 collected.

Example 3

[0192] Synthesis of Multinuclear Compound

[0193] This example describes an alternative synthesis of a multinuclearcompound of the invention. Synthesis of a imine-containing ligand andbinding of the ligand to the bridging group is as described in Examples1 and 2. Binding of a silicon-containing ligand to the semi-bridgedligand compound is described in part (a), metallation thesilicon-containing ligand is described in part (b) and metallation ofthe imine-containing ligand is described in part (c).

[0194] (a) Binding of a silicon-containing ligand to the semi-bridgedligand compound: The semi-bridged ligand compound 9, is synthesizedusing the methods described in Examples 1 and 2. As depicted in Scheme11, an approximately 1:2:1 molar ratio mixture of ligand 12, to NEt₃, tosemi-bridged ligand compound 9, is stirred at room temperature in THF toform the bridged ligand compound 13.

[0195] (b) Metallation of the bridged ligand compound: The Si-containingligands in the bridged compound is then metallated by reacting thecompound 13 with an approximately 1:2:1 molar ratio mixture of bridgedligand 13, to BuLi, to ZrCl₄, in diethylether to form semi-metallatedcompound 14 as illustrated below in Scheme 12.

[0196] (c) Metallation of the imine-containing ligand: Theimine-containing ligand in the bridged compound is then metallated byreacting the compound 14 with an equal molar amount of (COD)PdCl₂slurried in diethyl ether to form multinuclear compound 15 asillustrated in Scheme 13.

[0197] The mixture is then filtered, the solvent removed andmultinuclear compound 15 collected.

Example 4

[0198] Synthesis of Multinuclear Compound

[0199] This example describes synthesis of a multinuclear compound ofthe invention, with synthesis of a salicylaldimine ligand and bridgingcompound described in part (a), metallation of the salicylaldimineligand and bridging compound described in part (b), binding of themetallated ligand and bridging group to a silicon-containing liganddescribed in part(c) and metallation of the silicon-containing liganddescribed in part (d).

[0200] (a) Synthesis of the salicylaldimine ligand and bridgingcompound: The salicylaldimine ligand and bridging compound 16 wassynthesized as illustrated in Scheme 14. 2,5-Dihydroxybenzaldehyde(0.644 g) c was mixed with an equimolar amount of 2,6-dimethylaniline,b, in methanol and stirred for 16 hours at room temperature. Thesolution was then evaporated to dryness and extracted withdichloromethane. Hexane was then added, causing a black precipitate toform. The mixture was filtered to give a red gel. ′HNMR indicted thatthe red gel was salicylaldimine ligand 16, 2.20 (s, 6H), 6.82 (s, 1H),6.96 (s, 2H), 7.03 (m, 1H), 7.10 (m, 2H), 8.23 (s, 1H).

[0201] (b) Metallation of the salicylaldimine ligand and bridgingcompound: The salicylaldimine ligand in the salicylaldimine ligand andbridging compound is then metallated by reacting the compound 16 with anapproximately 1:1:1 molar ratio mixture of compound 16, to NaH, totrans-(PPh₃)₂Ni(Ph)Cl, in THF to form metallated compound 17 asillustrated below in Scheme 15.

[0202] (c) Binding of a silicon-containing ligand to the metallatedcompound: As depicted in Scheme 16, an approximately 1:1:1 molar ratiomixture of ligand 12, to NEt₃, to semi-metallated compound 17, isstirred at room temperature in diethyl ether to form the semi-metallatedbridged compound 18,

[0203] (d) Metallation of the semi-metallated bridged compound: Theimine-containing ligands in the semi-metallated bridged compound is thenmetallated by reacting the compound 18 with an equal molar amount ofZr(NMe₂)₄ in diethyl ether to form multinuclear compound 19 asillustrated below in Scheme 17.

Example 5

[0204] Prepatation of Bimodal Polyethylene

[0205] The metallocene compounds prepared in Example 2 is used aspolymerization catalysts in the preparation of polyethylene (“PE”)having a bimodal branching distribution. Standard ethylenepolymerization conditions are used, as follows: Polymerizations areconducted in a 300 mL autoclave reactor. Methyl aluminoxane (MAO) isused as co-catalyst with total Al/M ratio equal to 300. Prior toinitiation of polymerization, the reactors are loaded with 160 mL oftoluene and the MAO. The reactors are heated to the desired reactiontemperature and pressurized with ethylene to 100 psig. The reactors areconfigured to maintain the set pressure and temperature during thepolymerization reaction. The reaction is initiated by injection of thecatalyst. The reactions are run for 30 minutes and terminated byinjection of acidified methanol (2% HCl). The polymer is removed fromthe reactor and washed with additional acidified methanol, aqueousNaHCO₃, water and acetone. The resulting polymer is dried in a vacuumoven overnight and displays a bimodal molecular weight distribution.

We claim:
 1. A compound comprising an organometallic complex useful as apolymerization catalyst, having two or more different active sites, atleast one of which is comprised of a transition metal atom M¹coordinated to an unsaturated nitrogenous ligand.
 2. The compound ofclaim 1, wherein M¹ is selected from the group consisting of V, Nb, Ta,Cr, Mo, W, Mn and Re.
 3. The compound of claim 1, wherein theunsaturated nitrogenous ligand contains a first coordinating atom thatis a nitrogen atom contained within a C═N group, and a secondcoordinating atom that is either a second nitrogen atom, which may ormay not be present in a second C═N group, or an oxygen, sulfur orphosphorus atom.
 4. The compound of claim 3, wherein the secondcoordinating atom is a second nitrogen atom.
 5. The compound of claim 4,wherein the second nitrogen atom is present in a second C═N group. 6.The compound of claim 1, wherein the unsaturated nitrogenous ligand hasthe structure of formula (I)

wherein: q is an optional double bond, and X is N, O, S or P, with theprovisos that (a) when X is N or P, then either n is 1 or q is presentas a double bond, but not both, and (b) when X is O or S, then n is zeroand q is absent; R¹, R⁶, and R⁷ are independently hydrido, hydrocarbylor substituted hydrocarbyl, and R² and R⁵ are independently hydrido,halo, hydrocarbyl or substituted hydrocarbyl, or R¹ and R² and/or R⁵ andR⁶ may be taken together to form a linkage —Q*—, resulting in a five- orsix-membered ring, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— in which a* is2, 3 or 4, Z is N, O or S, b* is zero, 1 or 2, the sum of a* and b* is 3or 4, and R* is selected from the group consisting of hydrido, halo,hydrocarbyl, hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹, and NO₂ whereinR⁸ and R⁹ are each independently hydrocarbyl, or wherein R* moieties onadjacent carbon atoms may be linked to form an additional five- orsix-membered ring, or R² and R⁵ may together form a linkage —Q*— as justdefined; R³ and R⁴ are independently selected from the group consistingof hydrido and hydrocarbyl; and l, m, and n are independently zero or 1.7. The compound of claim 6, wherein X is N, q represents a double bond,and n is zero.
 8. The compound of claim 7, wherein X is O, q is absentand n is zero.
 9. The compound of claim 1, wherein two of the activesites are comprised of a transition metal coordinated to an unsaturatednitrogenous ligand.
 10. The compound of claim 1, wherein one of theactive sites is comprised of a metal atom M² coordinated to one or morecyclopentadienyl moieties (II)

wherein: M² is a transition metal, a lanthanide or an actinide; R and R′are independently selected from the group consisting of halogen, C₁-C₂₄hydrocarbyl, C₁-C₂₄ hydrocarbyl substituted with one or more halogenatoms, and C₁-C₂₄ hydrocarbyl-substituted Group IVB elements; x is 0, 1,2, 3 or 4, and y is 0, 1, 2, 3 or 4, with the proviso that the sum of xand y cannot exceed 4, or, when R and R′ are ortho to each other and xand y are each 1 or greater, R and R′ they can together form a five- orsix-membered cyclic structure optionally substituted with one to foursubstituents selected from the group consisting of halogen, C₁-C₂₄hydrocarbyl, C₁-C₂₄ hydrocarbyl substituted with one or more halogenatoms, and C₁-C₂₄ hydrocarbyl-substituted Group IVB elements.
 11. Acompound comprising an organometallic complex useful as a polymerizationcatalyst having the structure of formula (III)

wherein: B is a covalent bridging group comprising carbyl, silyl,disilyl, germanyl, ammonium, phosphonium,

 or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterohydrocarbylene radicaloptionally containing a Group IVB element, a Group VB element, or both aGroup IVB element and a Group VB element, and is capable of binding upto n_(max) substituents through single covalent bonds, wherein n_(max)is at least 4; R and R′ are independently selected from the groupconsisting of halogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄hydrocarbyl-substituted Group IVB elements; x is 0, 1, 2, 3 or 4, and yis 0, 1, 2, 3 or 4, with the proviso that the sum of x and y cannotexceed 4, or, when R and R′ are ortho to each other and x and y are each1 or greater, R and R′ they can together form a five- or six-memberedcyclic structure optionally substituted with one to four substituentsselected from the group consisting of halogen, C₁-C₂₄ hydrocarbyl,C₁-C₂₄ hydrocarbyl substituted with one or more halogen atoms, andC₁-C₂₄ hydrocarbyl-substituted Group IVB elements, q is an optionaldouble bond, and X is N, O, S or P, with the provisos that (a) when X isN or P, then either n is 1 or q is present as a double bond, but notboth, and (b) when X is O or S, then n is zero and q is absent; R¹, R⁶,and R⁷ are independently hydrido, hydrocarbyl or substitutedhydrocarbyl, and R² and R⁵ are independently hydrido, halo, hydrocarbylor substituted hydrocarbyl, or R¹ and R² and/or R⁵ and R⁶ may be takentogether to form a linkage —Q*—, resulting in a five- or six-memberedring, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— in which a* is 2, 3 or 4, Zis N, O or S, b* is zero, 1 or 2, the sum of a* and b* is 3 or 4, and R*is selected from the group consisting of hydrido, halo, hydrocarbyl,hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹, and NO₂ wherein R⁸ and R⁹ areeach independently hydrocarbyl, or wherein R* moieties on adjacentcarbon atoms may be linked to form an additional five- or six-memberedring, or R² and R⁵ may together form a linkage —Q*— as just defined; R³and R⁴ are independently selected from the group consisting of hydridoand hydrocarbyl; k, l, m, and n are independently zero or 1; Q¹, Q², Q³and Q⁴ are independently selected from the group consisting of univalentradicals; Q⁵ is an optional ligand having the structure of formula (I)

 wherein: q, X, R¹, R², R³, R⁵, R⁴, R⁶, R⁷, l, m, and n are as definedabove; M¹ is a transition metal; M² is a Group IIIA element, a Group IVAelement, a Group VA element, a lanthanide, or an actinide; Q isJ(R^(x))_(z-2) wherein J is an element with a coordination number ofthree from Group VB or an element with a coordination number of two fromGroup VIB, R^(x) is selected from the group consisting of hydrogen,C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbyl substituted with one or morehalogen atoms, and C₁-C₂₄ alkoxy, and z is the coordination number of J,and further wherein Q substituents on different L groups are linkedthrough a C₁-C₂₄ hydrocarbylene bridge; a is at least 1, b is 0, 1 or 2,and the sum of a and b is 2 or
 3. 12. The compound of claim 11, whereina is 1 and b is
 1. 13. The compound of claim 12, wherein a is 1 and b is2.
 14. The compound of claim 12, wherein a is 2 and b is
 0. 15. Thecompound of claim 12, wherein, in Formula (III): B is a covalentbridging group comprising carbyl, silyl, disilyl or a C₁-C₃₀hydrocarbylene, substituted hydrocarbylene, heterohydrocarbylene, orsubstituted heterohydrocarbylene radical optionally containing a GroupIVB element, a Group VB element, or both; x is 0, 1 or 2; y is 0, 1 or2; R and R′ are independently selected from the group consisting ofhalogen and C₁-C₁₂ alkyl, or are ortho to each other and linked to forma cyclopentadienyl or indenyl group; J is nitrogen, phosphorus, oxygenor sulfur, and R″ is C₁-C₁₂ alkyl, C₁-C₁₂ alkylsubstituted with ahalogen atom, or monocyclic aryl; M¹ is selected from the groupconsisting of V, Nb, Ta, Cr, Mo, W, Mn and Re; and X is N and qrepresents a double bond.
 16. A compound comprising an organometalliccomplex useful as a polymerization catalyst, having two or moredifferent active sites, at least one of which is comprised of a metalatom M¹ coordinated to a ligand having the structure of formula (IV)

wherein: R¹⁰, R¹¹, R¹² and R¹³ are independently, hydrocarbyl orsubstituted hydrocarbyl; and i and j are independently zero, 1, 2 or 3.17. The compound of claim 16, wherein one of the active sites iscomprised of a metal atom M² coordinated to one or more moieties (II)

wherein: M² is a Group IIIA element, a Group IVA element, a Group VAelement, a lanthanide or an actinide; R and R′ are independentlyselected from the group consisting of halogen, C₁-C₂₄ hydrocarbyl,C₁-C₂₄ hydrocarbyl substituted with one or more halogen atoms, andC₁-C₂₄ hydrocarbyl-substituted Group IVB elements; x is 0, 1, 2, 3 or 4,and y is 0, 1, 2, 3 or 4, with the proviso that the sum of x and ycannot exceed 4, or, when R and R′ are ortho to each other and x and yare each 1 or greater, R and R′ they can together form a five- orsix-membered cyclic structure optionally substituted with one to foursubstituents selected from the group consisting of halogen, C₁-C₂₄hydrocarbyl, C₁-C₂₄ hydrocarbyl substituted with one or more halogenatoms, and C₁-C₂₄ hydrocarbyl-substituted Group IVB elements.
 18. Acompound comprising an organometallic complex useful as a polymerizationcatalyst having the structure of formula (V)

wherein: B is a covalent bridging group comprising carbyl, silyl,disilyl, germanyl, ammonium, phosphonium,

 or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterohydrocarbylene radicaloptionally containing a Group IVB element, a Group VB element, or both aGroup IVB element and a Group VB element, and is capable of binding upto n_(max) substituents through single covalent bonds, wherein n_(max)is at least 4; R and R′ are independently selected from the groupconsisting of halogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄hydrocarbyl-substituted Group IVB elements; x is 0, 1, 2, 3 or 4, and yis 0, 1, 2, 3 or 4, with the proviso that the sum of x and y cannotexceed 4, or, when R and R′ are ortho to each other and x and y are each1 or greater, R and R′ they can together form a five- or six-memberedcyclic structure optionally substituted with one to four substituentsselected from the group consisting of halogen, C₁-C₂₄ hydrocarbyl,C₁-C₂₄ hydrocarbyl substituted with one or more halogen atoms, andC₁-C₂₄ hydrocarbyl-substituted Group IVB elements, Q¹, Q², Q³ and Q⁴ areindependently selected from the group consisting of univalent radicals;Q⁵ is an optional ligand having the structure of formula (I)

 wherein: q is an optional double bond, and X is N, O, S or P, with theprovisos that (a) when X is N or P, then either n is 1 or q is presentas a double bond, but not both, and (b) when X is O or S, then n is zeroand q is absent; R¹, R⁶, and R⁷ are independently hydrido, hydrocarbylor substituted hydrocarbyl, and R² and R⁵ are independently hydrido,halo, hydrocarbyl or substituted hydrocarbyl, or R¹ and R² and/or R⁵ andR⁶ may be taken together to form a linkage —Q*—, resulting in a five- orsix-membered ring, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— in which a* is2, 3 or 4, Z is N, O or S, b* is zero, 1 or 2, the sum of a* and b* is 3or 4, and R* is selected from the group consisting of hydrido, halo,hydrocarbyl, hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹, and NO₂ whereinR⁸ and R⁹ are each independently hydrocarbyl, or wherein R* moieties onadjacent carbon atoms may be linked to form an additional five- orsix-membered ring, or R² and R⁵ may together form a linkage —Q*— as justdefined; R³ and R⁴ are independently selected from the group consistingof hydrido and hydrocarbyl; k, l, m, and n are independently zero or 1;M¹ is a transition metal; M² is a transition metal, a lanthanide, or anactinide; Q is J(R^(x))_(z-2) wherein J is an element with acoordination number of three from Group VB or an element with acoordination number of two from Group VIB, R^(x) is selected from thegroup consisting of hydrogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄ alkoxy, and z isthe coordination number of J, and further wherein Q substituents ondifferent L groups are linked through a C₁-C₂₄ hydrocarbylene bridge; ais at least 1, b is 0, 1 or 2, and the sum of a and b is 2 or 3; R¹⁰,R¹¹, R¹² and R¹³ are independently, hydrocarbyl or substitutedhydrocarbyl; and i and j are independently zero, 1, 2 or
 3. 19. Acompound comprising an organometallic complex useful as a polymerizationcatalyst having the structure of formula (VII)

wherein: B is a covalent bridging group comprising carbyl, silyl,disilyl, germanyl, ammonium, phosphonium,

 or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterohydrocarbylene radicaloptionally containing a Group IVB element, a Group VB element, or both aGroup IVB element and a Group VB element, and is capable of binding upto n_(max) substituents through single covalent bonds, wherein n_(max)is at least 4; R and R′ are independently selected from the groupconsisting of halogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄hydrocarbyl-substituted Group IVB elements; x is 0, 1, 2, 3 or 4, and yis 0, 1, 2, 3 or 4, with the proviso that the sum of x and y cannotexceed 4, or, when R and R′ are ortho to each other and x and y are each1 or greater, R and R′ they can together form a five- or six-memberedcyclic structure optionally substituted with one to four substituentsselected from the group consisting of halogen, C₁-C₂₄ hydrocarbyl,C₁-C₂₄ hydrocarbyl substituted with one or more halogen atoms, andC₁-C₂₄ hydrocarbyl-substituted Group IVB elements, Q¹, Q², Q³ and Q⁴ areindependently selected from the group consisting of univalent radicals;Q⁵ is an optional ligand having the structure of formula (I)

 wherein: q is an optional double bond, and X is N, O, S or P, with theprovisos that (a) when X is N or P, then either n is 1 or q is presentas a double bond, but not both, and (b) when X is O or S, then n is zeroand q is absent; R¹, R⁶, and R⁷ are independently hydrido, hydrocarbylor substituted hydrocarbyl, and R² and R⁵ are independently hydrido,halo, hydrocarbyl or substituted hydrocarbyl, or R¹ and R² and/or R⁵ andR⁶ may be taken together to form a linkage —Q*—, resulting in a five- orsix-membered ring, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— in which a* is2, 3 or 4, Z is N, O or S, b* is zero, 1 or 2, the sum of a* and b* is 3or 4, and R* is selected from the group consisting of hydrido, halo,hydrocarbyl, hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹, and NO₂ whereinR⁸ and R⁹ are each independently hydrocarbyl, or wherein R* moieties onadjacent carbon atoms may be linked to form an additional five- orsix-membered ring, or R² and R⁵ may together form a linkage —Q*— as justdefined; R³ and R⁴ are independently selected from the group consistingof hydrido and hydrocarbyl; k, l, m, and n are independently zero or 1;M¹ is a transition metal; M² is a transition metal, a lanthanide, or anactinide; Q is J(R^(x))_(z-2) wherein J is an element with acoordination number of three from Group VB or an element with acoordination number of two from Group VIB, R^(x) is selected from thegroup consisting of hydrogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄ alkoxy, and z isthe coordination number of J, and further wherein Q substituents ondifferent L groups are linked through a C₁-C₂₄ hydrocarbylene bridge; ais at least 1, b is 0, 1 or 2, and the sum of a and b is 2 or 3; R¹² andR¹³ are independently, hydrocarbyl or substituted hydrocarbyl; and i andj are independently zero, 1, 2 or
 3. 20. A compound comprising anorganometallic complex useful as a polymerization catalyst having thestructure of formula (VIII)

wherein: B is a covalent bridging group comprising carbyl, silyl,disilyl, germanyl, ammonium, phosphonium,

 or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterohydrocarbylene radicaloptionally containing a Group IVB element, a Group VB element, or both aGroup IVB element and a Group VB element, and is capable of binding upto n_(max) substituents through single covalent bonds, wherein n_(max)is at least 4; q is an optional double bond, and X is N, O, S or P, withthe provisos that (a) when X is N or P, then either n is 1 or q ispresent as a double bond, but not both, and (b) when X is o or S, then nis zero and q is absent; R¹, R⁶, and R⁷ are independently hydrido,hydrocarbyl or substituted hydrocarbyl, and R² and R⁵ are independentlyhydrido, halo, hydrocarbyl or substituted hydrocarbyl, or R¹ and R²and/or R⁵ and R⁶ may be taken together to form a linkage —Q*—, resultingin a five- or six-membered ring, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— inwhich a* is 2, 3 or 4, Z is N, O or S, b* is zero, 1 or 2, the sum of a*and b* is 3 or 4, and R* is selected from the group consisting ofhydrido, halo, hydrocarbyl, hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹,and NO₂ wherein R⁸ and R⁹ are each independently hydrocarbyl, or whereinR* moieties on adjacent carbon atoms may be linked to form an additionalfive- or six-membered ring, or R² and R⁵ may together form a linkage—Q*— as just defined; R³ and R⁴ are independently selected from thegroup consisting of hydrido and hydrocarbyl; h, k, l, m, and n areindependently zero or 1; Q¹, Q², Q³ and Q⁴ are independently selectedfrom the group consisting of univalent radicals; Q⁵ and Q⁶ areindependently optional ligands having the structure of formula (I)

 wherein: R¹, R², R³, R⁴, R⁵, R⁶, R⁷, q, l, m and n are independently asdescribed above; M¹ is a transition metal; M² is a transition metal, alanthanide, or an actinide; Q is J(R^(x))_(z-2) wherein J is an elementwith a coordination number of three from Group VB or an element with acoordination number of two from Group VIB, R^(x) is selected from thegroup consisting of hydrogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄ alkoxy, and z isthe coordination number of J, and further wherein Q substituents ondifferent L groups are linked through a C₁-C₂₄ hydrocarbylene bridge; ais at least 1, b is 0, 1 or 2, and the sum of a and b is 2 or 3; R¹² andR¹³ are independently, hydrocarbyl or substituted hydrocarbyl; and i andj are independently zero, 1, 2 or
 3. 21. A compound comprising anorganometallic complex useful as a polymerization catalyst having thestructure of formula (IX)

wherein: B is a covalent bridging group comprising carbyl, silyl,disilyl, germanyl, ammonium, phosphonium,

 or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterohydrocarbylene radicaloptionally containing a Group IVB element, a Group VB element, or both aGroup IVB element and a Group VB element, and is capable of binding upto n_(max) substituents through single covalent bonds, wherein n_(max)is at least 4; q is an optional double bond, and X is N, O, S or P, withthe provisos that (a) when X is N or P, then either n is 1 or q ispresent as a double bond, but not both, and (b) when X is O or S, then nis zero and q is absent; R¹, R⁶, and R⁷ are independently hydrido,hydrocarbyl or substituted hydrocarbyl, and R² and R⁵ are independentlyhydrido, halo, hydrocarbyl or substituted hydrocarbyl, or R¹ and R²and/or R⁵ and R⁶ may be taken together to form a linkage —Q*—, resultingin a five- or six-membered ring, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— inwhich a* is 2, 3 or 4, Z is N, O or S, b* is zero, 1 or 2, the sum of a*and b* is 3 or 4, and R* is selected from the group consisting ofhydrido, halo, hydrocarbyl, hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹,and NO₂ wherein R⁸ and R⁹ are each independently hydrocarbyl, or whereinR* moieties on adjacent carbon atoms may be linked to form an additionalfive- or six-membered ring, or R² and R⁵ may together form a linkage—Q*— as just defined; R³ and R⁴ are independently selected from thegroup consisting of hydrido and hydrocarbyl; h, k, l, m, and n areindependently zero or 1; Q¹, Q², Q³ and Q⁴ are independently selectedfrom the group consisting of univalent radicals; Q⁵ and Q⁶ areindependently optional ligands having the structure of formula (I)

 wherein: R¹, R², R³, R⁴ , R⁵ , R⁶, R⁷, q, l, m and n are independentlyas described above; M¹ is a transition metal; M² is a transition metal,a lanthanide, or an actinide; a is at least 1, b is 0, 1 or 2, and thesum of a and b is 2 or 3; R¹³ is independently, hydrocarbyl orsubstituted hydrocarbyl; and i is zero, 1, 2 or
 3. 22. A compoundcomprising an organometallic complex useful as a polymerization catalysthaving the structure of formula (X)

wherein: B is a covalent bridging group comprising carbyl, silyl,disilyl, germanyl, ammonium, phosphonium,

 or a C₁-C₃₀ hydrocarbylene, substituted hydrocarbylene,heterohydrocarbylene or substituted heterohydrocarbylene radicaloptionally containing a Group IVB element, a Group VB element, or both aGroup IVB element and a Group VB element, and is capable of binding upto n_(max) substituents through single covalent bonds, wherein n_(max)is at least 4; R and R′ are independently selected from the groupconsisting of halogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄hydrocarbyl-substituted Group IVB elements; x is 0, 1, 2, 3 or 4, and yis 0, 1, 2, 3 or 4, with the proviso that the sum of x and y cannotexceed 4, or, when R and R′ are ortho to each other and x and y are each1 or greater, R and R′ they can together form a five- or six-memberedcyclic structure optionally substituted with one to four substituentsselected from the group consisting of halogen, C₁-C₂₄ hydrocarbyl,C₁-C₂₄ hydrocarbyl substituted with one or more halogen atoms, andC₁-C₂₄ hydrocarbyl-substituted Group IVB elements, Q¹, Q², Q³ and Q⁴ areindependently selected from the group consisting of univalent radicals;Q⁵ is an optional ligand having the structure of formula (I)

 wherein: q is an optional double bond, and X is N, O, S or P, with theprovisos that (a) when X is N or P, then either n is 1 or q is presentas a double bond, but not both, and (b) when X is O or S, then n is zeroand q is absent; R¹, R⁶, and R⁷ are independently hydrido, hydrocarbylor substituted hydrocarbyl, and R² and R⁵ are independently hydrido,halo, hydrocarbyl or substituted hydrocarbyl, or R¹ and R² and/or R⁵ andR⁶ may be taken together to form a linkage —Q*—, resulting in a five- orsix-membered ring, wherein Q* is —[(CR*)_(a*)(Z)_(b*)]— in which a* is2, 3 or 4, Z is N, O or S, b* is zero, 1 or 2, the sum of a* and b* is 3or 4, and R* is selected from the group consisting of hydrido, halo,hydrocarbyl, hydrocarbyloxy, trialkylsilyl, NR⁸ ₂, OR⁹, and NO₂ whereinR⁸ and R⁹ are each independently hydrocarbyl, or wherein R* moieties onadjacent carbon atoms may be linked to form an additional five- orsix-membered ring, or R² and R⁵ may together form a linkage —Q*— as justdefined; R³ and R⁴ are independently selected from the group consistingof hydrido and hydrocarbyl; k, l, m, and n are independently zero or 1;M¹ is a transition metal; M² is a transition metal, a lanthanide, or anactinide; Q is J(R^(x))_(z-2) wherein J is an element with acoordination number of three from Group VB or an element with acoordination number of two from Group VIB, R^(x) is selected from thegroup consisting of hydrogen, C₁-C₂₄ hydrocarbyl, C₁-C₂₄ hydrocarbylsubstituted with one or more halogen atoms, and C₁-C₂₄ alkoxy, and z isthe coordination number of J, and further wherein Q substituents ondifferent L groups are linked through a C₁-C₂₄ hydrocarbylene bridge; ais at least 1, b is 0, 1 or 2, and the sum of a and b is 2 or 3; R¹³ isindependently, hydrocarbyl or substituted hydrocarbyl; and j is zero, 1,2 or
 3. 23. A method for preparing a polymer composition, comprising:contacting, under polymerization conditions, an addition polymerizablemonomer having at least one degree of unsaturation with a catalystsystem comprising the compound of claim 1 and a catalyst activatoreffective to produce a catalytically active ionic species when combinedwith said compound.
 24. The method of claim 23, wherein the additionpolymerizable monomer is an olefinic or vinyl monomer.
 25. The method ofclaim 24, wherein the addition polymerizable monomer is ethylene. 26.The method of claim 24, wherein the addition polymerizable monomer ispropylene.
 27. The method of claim 23, wherein the catalyst activator isaluminum-containing or boron-containing.
 28. The method of claim 27,wherein the catalyst activator is aluminum-containing.
 29. The method ofclaim 28, wherein the catalyst activator is an organoaluminum compound.30. The method of claim 29, wherein the catalyst activator is an alkylaluminoxane.
 31. The method of claim 30, wherein the catalyst activatoris methyl aluminoxane.
 32. The method of claim 27, wherein the catalystactivator is boron-containing.
 33. The method of claim 32, wherein thecatalyst activator is a fluorohydrocarbylboron compound.
 34. The methodof claim 32, wherein the catalyst activator is a fluorinatedphenylborate.
 35. The method of claim 23, wherein the catalyst systemfurther includes an inert polymerization diluent.
 36. The method ofclaim 35, wherein the diluent is a volatile hydrocarbon solvent.